Overwatch 2 Season 6 Underworld Event: Challenges, Rewards, Duration, More
Who is your partner in crime to complete these?

Cover-Credits:
The entire Overwatch 2 community could only talk about the PvE (Player versus Environment) Co-Op Story Missions that were headed to the game prior to the release of Overwatch 2 Season 6 Invasion.
It was not what the developers had initially promised before the release of this game, but at least the lore was being worked upon, and after a long time it was the center of attention.
Unfortunately, Story Missions were not free and players had to pay a one-time fee to experience it. Thankfully, the developers also offered some free Story Missions as part of the Underworld Event.
This does not follow the main lore but is centered around it to offer players a co-op experience, along with various rewards including Sparkplug Brigitte Legendary Skin for completing certain challenges.
Overwatch 2 Season 6 Underworld Event: Complete Details
Story Missions have received a sound response from the community but not everyone can afford to purchase them. Hence, Overwatch 2 has also launched the Underworld Event which offers side missions with a similar PvE experience on King's Row.
Underworld Event is around for about four weeks from 10th August to 5th September.
Every week a new mission will be added for players to try out, as they defeat waves of robots with a team of four Heroes to achieve an objective.
There are 16 different challenges that players can complete during the Underworld Event, each consisting of a reward that either offers a cosmetic item, a battle pass experience, or both.
Underworld Event: Challenges and Reward
There are a total of 16 challenges but only 10 of them guarantee a cosmetic item as a reward, others offer battle pass experience which are also important to complete the Overwatch 2 Season 6 Battle Pass.
Underworld Fighter | 5000 XP
Complete Underworld on any difficulty.
Underworld: Missile Fighter | 5000 XP
Complete Underworld: Death From Above on any difficulty.
Underworld: Role Master | Brigitte Player Icon: Sparkplug
Complete Underworld on each role.
Tank, Damage, and Support.
Stop, Thief! | Spray: TS-1 Repairs
Eliminate four battery thieves as a team before they steal a battery in a single, completed run of Underworld.
You’re Welcome, Human! | 2500 XP
Activate TS-1’s gratitude protocol in Underworld.
Underworld: Lore Hunter | Spray: Vulture
Discover all hidden lore interactions as a team in Underworld.
Anti-Omnic Graffiti, Mondatta Memorial, Lucio Record, Underworld Sign, and Lucio Concert Poster.
Nulltimate | 2500 XP
Prevent the A-7000 and OR Units from using their ultimates and complete Underworld.
Rock On TS-1 | Spray: We Are One
Keep TS-1 alive and complete Underworld.
Underworld: Expert Fighter | Tracer Voice Line: Crash Another Party
Complete Underworld on Expert difficulty.
Underworld: Expert Missile Fighter | Solider 76 Voice Line: Fighting For
Complete Underworld: Death From Above on Expert difficulty.
Underworld: Modified Master | Player Title: Underworld Guardian
Complete Underworld on Legendary difficulty with each of the three weekly modifiers.
Death From Above, Ultimate Zones, and Invasion Mystery Swap.
Underworld: Ultimate Fighter | 5000 XP
Complete Underworld: Ultimate Zones on any difficulty.
Underworld: Mystery Fighter | 5000 XP
Complete Underworld: Invasion Mystery Swap on any difficulty.
Underworld: Expert Ultimate Fighter | Ashe Voice Line: Long Way From Home
Complete Underworld: Ultimate Zones on Expert difficulty.
Underworld: Expert Mystery Fighter | Zenyatta Voice Line: Suffering and Persistence
Complete Underworld: Invasion Mystery Swap on Expert difficulty.
Savior of the Underworld | Sparkplug Brigitte Legendary Skin
Complete any 8 Underworld event challenges.
Most of the challenges for the Underworld Event are pretty straightforward, requiring players to accomplish simple tasks where as others might require a well-cordinated team and some snooping around the map during the missions.
Hopefully, players will be able to complete these tasks before time runs out because it is around till 5th September only. In case you are late to the party there is still time, you just need to hurry up a bit.